[Dovecot] Error Building v2.2

[Nikolaos Milas]

Hello,

I am trying to build Dovecot v2.2 (nightly version 20130326, which I 
have renamed and use as 2.2.0) on CentOS 6.4 x86_64 and I am having a 
problem:
...
+ ./configure --build=x86_64-redhat-linux-gnu 
--host=x86_64-redhat-linux-gnu --target=x86_64-redhat-linux-gnu 
--program-prefix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin 
--sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share 
--includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec 
--localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man 
--infodir=/usr/share/info 'INSTALL_DATA=install -c -p -m644' 
--docdir=/usr/share/doc/dovecot-2.2.0 --disable-static --disable-rpath 
--with-nss --with-shadow --with-pam --with-gssapi=plugin 
--with-ldap=plugin --with-sql=plugin --with-pgsql --with-mysql 
--with-sqlite --with-zlib --with-libcap --with-ssl=openssl 
--with-ssldir=/etc/pki/dovecot --with-solr --with-docs --with-bzlib
configure: error: unrecognized option: --docdir=/usr/share/doc/dovecot-2.2.0

I found here: http://www.dovecot.org/list/dovecot/2011-April/058420.html 
that --docdir option exists when autoconf version > 2.60.

Yet:

    $ rpm -qa | grep autoconf
    autoconf-2.63-5.1.el6.noarch

So, what may be wrong?

Please help.

Thanks,
Nick